Each recipe is orange until its yellow rank and grey from its grey rank. When the ranks differ, it turns green somewhere between the two; the client files give both ranks but not that point. Equal ranks go straight to grey.

Blacksmithing: Camping
RecipeMakesReagentsNeedsSkill-up
Sharpening Wheel
Sharpening WheelYellow 20Grey 25
AnvilTaught by Blueprint: Anvil, requires 140
AnvilYellow 140Grey 145
Master ForgeTaught by Blueprint: Master Forge, requires 300
Master ForgeGrey 300

From the Forever beta client files, build 1.60.1.70630: the SkillLine, SkillLineAbility, TradeSkillCategory, SpellReagents, SpellEffect, SpellTotems, SpellCastingRequirements and ItemEffect tables.